Fumferknuckle

I am confused as how to do this. I download the files and remove the .stash and put it in the lib folder. That didn't work. So then I redownloaded the files and opened with 7zip and deleted the .stash and the change I made to the name doesn't save. Can you give a more detailed step-by-step guide please? I am just having difficulties for some reason. Also, here is what my problem is. I can launch the Tekkit pack and everything fine. When I try to start a single player game, or log in to the server I am renting, it says logging in, then that text dissapears and it shows the dirt wall background for a while, then it goes windowed and the screen goes completely white, like it is trying to show an error message, then just closes completely with no error message. No error sounds or anything. I don't understand why it just doesn't launch. I have tried reinstalling java, the launcher, deleted the .tekkit folder and reinstalled the folder, consulted with the people who I am renting the server from, everything. I was able to launch Hexxit servers easily, no problems. Ran smooth and everything. I can do vanilla Minecraft and even Feed the Beast. But when it comes to Tekkit my computer just derps. Your help is very appreciated!